One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,16)(12,23,27,39)(13,18)(14,29)(15,19)(17,25,35,26)(20,36,37,34)(21,31)(22,33)(24,38,40,30)(28,32)(1,3,5,4)(2,6,8,7)(9,11,15,22)(10,16,19,33)(12,24)(13,28,14,21)(17,34)(18,32,29,31)(20,25)(23,38)(26,37)(27,40)(30,39)(35,36)(1,3,5,4)(2,7,8,6)(9,12)(10,17,19,35)(11,20,22,37)(13,25)(14,26)(15,27)(16,30)(18,23,29,39)(21,24,28,40)(31,36)(32,34)(33,38)(1,4,5,3)(2,7,8,6)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.